mmc2 on beaglebone black

Dear all,

according to AM335xx TRM, a beaglebone black should have 3 mmc available:
→ mmc0 (sd card)
→ mmc1 (2G flash)
→ mmc2.

I am trying to enable mmc2 by device tree (and I am quite sure to have the right pin settings) but, by doing
I obtain:

/ocp/mmc@47810000: can’t find DMA channel
omap_hsmmc mmc.11: unable to obtain RX DMA engine channel 65

By putting the oscilloscope probe on the header (e.g. the mmc2_clk signal), I do not see any transition.
I already removed R 160 to have mmc2_cmd accessible but I do not see any transition also there.

I tried both to enable it by echo > /sys/devices/…/slots and by “capemgr.enable_partno” with no success:
I can see it in /sys/devices/…/slots (with the L meaning loaded)…but no way to see any signal on the header.

I already googled it but answers are not clear at all.
Did someone have success where I am failing?

My uname -a is:
Linux beaglebone 3.8.13 #1 SMP Tue Jun 18 02:11:09 EDT 2013 armv7l GNU/Linux

Thanks for your help.


no results…searched a lot around but…nothing.